How to Search the Internet by Chemical Structure

iScienceSearch is a search engine for chemists & biologists that lets you search many structure databases from PubChem to Wikipedia in one go. You can search, by structure, substructure, similarity, text and synonyms.

By Alexander Kos, (AKos Consulting).

An obvious way to search on the Internet by chemical structure is to search  many of hundreds existing databases, like PubChem, ChemSpider, Abblis Chemicals LLC, ACS Publications; Advanced Technology, AKosSamples, Alfa Aesar, … , Wikipedia, ZINC.

iScienceSearch, the Internet search engine for chemists & biologists, is a free Internet application that lets you search over all these in one go. You can search, by structure, substructure, similarity, text and synonyms.


Once you choose your entry option you need to chooses a profile:


The boxes beneath the structure are preconfigured profiles. Out of more than 100 databases, we choose these databases that are important for your query.

  • Suppliers – if you want to buy a compound
  • All journals – if you want a reference
  • MSDS – if you need a MSDS
  • Patents – if you want to search the public patent literature

Extended Search:If you type a name, iScienceSearch generates in the background automatically the chemical structure, the CAS Registry Number, other identifiers like AKOS number, and different names, if possible. We call this extended search. This means if you type Tamiflu, you also get answers that are perfectly correct, and where only the word Oseltamivir appears. Oseltamivir is a synonym for Tamiflu.

The result page is not a simple html page. 1) You can group your hits, 2) you can see the query used by the extended search, 3) you can filter the hits by category, or 4) by keyword.


CAS Registry Number® and Synonym CAS Registry Number is a registered trademark of the American Chemical Society (ACS). All Rights Reserved.

Bio: Dr. Alexander Kos is the principal of AKos Consulting & Solutions GmbH , which sells compounds, software, and databases for chemical and pharmaceutical research & development.